I don't think it costs anything just to post an item. They only take a cut if your item sells. At least that was how it worked when I last looked. Either way, I think the RMAH is a necessary evil of sorts. People are going to buy and sell items for real money anyway. The only major downside that I see is that it gives Blizzard profit motive in regards to game design. It is better for them to make godly items necessary for completion of the game so that unless you are incredibly patient, you have to buy items on the AH. That is pretty much the current state of things anyway, I've only found a handful of upgrades for myself as I've been leveling. A large majority of what my character uses was bought on the AH. I likely wont use the RMAH regardless, unless I find something godly that I can make money on. I have no desire to spend real money on fake items, but I'm more than happy selling my fake items for real money.